1. Write. No seriously, just write. You can't become an author without writing something.
2. Focus on getting your thoughts on the paper. You can tidy up afterwards.
3. Challenge yourself. Set word counts to push yourself to do more.
4. Get someone to proofread your book. You'll be supprised to see how many things you miss.
5. Hire an editor for your first books. It makes a huge difference.